Be mature about it. Tell him you understand he could be a little embarrassed but there really is no need to, you're not desperate and it's okay just being friends. That until the day you're closer you won't bother, stuff like that. In short, make it something not important.

But I guess it depends on how you made your confession. If it was really dramatic and desperate, then yeah, you screwed up and I'm not sure you can do anything.